The present invention relates to a system for injecting a substance into the annular space surrounding a well tubular.
After a well has been drilled, a well tubular is introduced into the well. Such a well tubular can be a casing or a liner. The outside diameter of the casing is smaller than the inside diameter of the wellbore, providing thereby an annular space, or annulus, between the casing and the wellbore. The well tubular is perforated at one or more zones to allow hydrocarbons to flow into the tubular. Sometimes contaminants such as water or sand are produced along with hydrocarbons from a part of the formations around a well tubular. Therefore it is sometimes required to seal off the well tubular from a part of the annular space containing undesirable contaminants.
To seal off a desired part of for example a casing one technique used is to isolate an internal part of the casing using temporary packers. Cement or other hardenable substance is then pumped down to the isolated zone to seal the perforated openings in the desired part of the casing. If production later on is desired from a zone situated further down in the casing, removal or penetration of the hardened zone is then required.
U.S. Pat. No. 6,955,216 discloses a device for injecting a fluid into an earth formation surrounding a well. The device comprises a body suitable for being arranged in a well bore and provided with a fluid chamber for storage of suitable sealant and a pair of inflatable packers arranged to isolate a portion of the well bore between the packers upon inflating of the packers. The suitable sealant is then injected under pressure into the formation through the perforations isolated between the packers.